The present invention relates to an image pickup apparatus having a lens barrier for protecting an image pickup lens.
An open/closable lens barrier is ordinarily provided on a front end portion of an image pickup lens in an image pickup apparatus such as a compact digital still camera for the purpose of preventing dust or a contaminant from being attached to the lens surface or preventing the lens surface from being damaged.
FIGS. 11 and 12 show a conventional lens barrier. FIG. 11 shows a state in which the lens barrier is closed. FIG. 12 shows a state in which the lens barrier is opened.
In FIGS. 11 and 12, reference numeral 201 denotes a lens barrel, reference numeral 208 denotes a light entrance aperture of the lens barrel, and reference numerals 202 and 203 denote barrier blades which are turned about shaft portions provided at their one ends between a closing position at which they close the light entrance aperture 208 and an opening position at which they open the light entrance aperture 208.
There is a demand for reducing the outer diameter of the lens barrel 201 with the reduction in camera size. However, in the arrangement in which, as shown in FIG. 11, the light entrance aperture 208 is completely closed with the two barrier blades 202 and 203, there is a possibility of portions 202a and 203a (hatched portions) of the barrier blades 202 and 203 at the opening position projecting beyond the outer diametrical ends of the lens barrel 201. This is an impediment to the reduction in diameter of the lens barrel.
Japanese Utility Model Laid-Open No. 3-18519 discloses a lens barrier in which two sets of barrier blades are used, each set consisting of a pair of barrier blades of a small size capable of being overlapped with each other and being extended. The lens barrier can close a large-area light entrance aperture when it is in the extended state and retract to a position outside the light entrance aperture when it is in the overlapped state.
However, if the size of each barrier blade is reduced, the strength of the barrier blade is so small that there is a possibility of the barrier blade being moved (displaced or deformed) in a direction toward the lens surface by even a small external force. In this case, the moved barrier blade scratches the lens surface or makes the lens barrier unable to operate. If the thickness of the barrier blade is increased for the purpose of increasing the strength thereof, the entire length of the lens barrel is increased.